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21 Nov 2016

#Risk #Assessment: Invasive #cardiovascular #infection by M. chimaera – 18 November 2016 (@ECDC_EU, summary)


Title: #Risk #Assessment: Invasive #cardiovascular #infection by M. chimaera – 18 November 2016.

Subject: Mycobacterium Chimaera, cardiac surgery device contamination; risk assessment.

Source: European Centre for Disease Prevention and Control (ECDC), full page: (LINK).

Code: [     ]



Invasive cardiovascular infection by M. chimaera – 18 November 2016


Suggested citation: European Centre for Disease Prevention and Control. Invasive cardiovascular infection by Mycobacterium chimaera associated with 3T heater-cooler system used during open-heart surgery – 18 November 2016. Stockholm: ECDC; 2016.

© European Centre for Disease Prevention and Control, Stockholm, 2016


Conclusions and options for response

  • Fifty-two cases of invasive cardiovascular infection caused by Mycobacterium chimaera have been detected in patients who had previously undergone open-heart surgery in seven countries in Europe (France, Germany, Ireland, the Netherlands, Spain, the UK and Switzerland) since 2011.
  • Cases have also been reported in the US, Canada, Australia and Hong-Kong Special Administrative Region.
  • Isolation of M. chimaera in heater-cooler units (HCUs) and in air samples suggests aerosolisation of water from the HCUs in the operating room as the most likely source of infection.
  • Contamination of the 3T heater-cooler system at the manufacturing site in Germany, has been identified as the most plausible source, which explains most but not all of invasive M. chimaera infections linked to this device.
  • Contamination during use at the hospital as well as involvement of other heater-cooler system models are also possible.
  • Relocation of HCUs to outside of the operating room, or other ways of strict separation of the HCU from the air volume of the operating room appear to be the safest measure.
  • However, this solution may not be feasible in every centre.
  • In such cases, if maintaining the HCU in the operating room is considered the only option, it should be placed at maximum distance from the operating table, the vent exhaust directed and channelled away from the patient and, if possible, close to the room air suction exhaust.
  • However, this option may not be sufficient to eliminate the risk.
  • Replacement of 3T HCUs manufactured before September 2014 with new devices of the same or other brands can be considered as a mitigating strategy.
  • However, it should be noted that the potential risks associated with other models remain to be defined.
  • Centres using 3T HCUs should strictly follow the instructions for use, and in particular those for cleaning and decontamination, issued by the manufacturer.
  • Establishing a quality control process with written procedures including traceability of the HCU used in each operation is also advisable. 
  • Healthcare providers (including cardiologists, pulmonologists, rheumatologists, infectious disease specialists, ophthalmologists, haematologists and primary care providers) caring for patients who have undergone openheart surgery or other surgery involving cardiopulmonary bypass, such as heart and/or lung transplantation, should be vigilant for cases of endocarditis or other cardiovascular, deep surgical site, or disseminated infection that are of unidentified origin.
  • They should also be vigilant for other granulomatous disease, including those with the characteristics of sarcoidosis, and consider testing such cases specifically for slow-growing NTM, such as M. chimaera . 
  • Other measures that EU/EEA countries may consider include informing patients who have undergone open-heart surgery involving exposure to 3T HCUs before the implementation of mitigation measures about the risk of acquisition and the signs and symptoms of infections with NTM, and in particular M. chimaera .
  • This is especially important if they were operated on in a centre that detected a case of M. chimaera previously. Accessible information should be readily available for healthcare providers and patients.
  • This information could be online, disseminated in the form of a letter to the patient, a patient information leaflet, or as frequently asked questions (FAQ).
  • An ECDC protocol is available for retrospective case detection, laboratory diagnosis and environmental testing of Mycobacterium chimaera .
  • Clinical and mycobacterial diagnostic investigations should be available and accessible for patients at risk after cardiovascular surgery to ensure prompt diagnosis and treatment.
  • Microbiological testing of water and air samples for the detection of M. chimaera and other NTM is technically challenging, with a high likelihood of false negative results.
  • Nevertheless, clinical vigilance, prospective case detection and notification of invasive cardiovascular infection caused by M. chimaera after open-heart surgery, as well as selective environmental testing, may be considered in the coming years in order to monitor the effectiveness of control measures, and ensure timely diagnosis and treatment for infected patients. 
  • Regulatory bodies in charge of licensing and agencies monitoring the safety of such devices should be aware of the association of invasive cardiovascular infections caused by M. chimaera and other NTM with HCUs and options for regulatory action should be considered.
  • Relevant information should be disseminated to all centres performing open-heart surgery or other surgery involving extracorporeal circulation.
  • Devices containing water circuits or using water during operation or maintenance and used in sensitive clinical areas should be carefully evaluated for the risk of contamination by NTM.



Keywords: ECDC; European Region; Updates; Mycobacterium Chimaera.